Download RealityGrid QT Steerering Application User Manual

RealityGrid Steering Application User Manual
Mark Riding and Andrew Porter.
SVE Group, Manchester Computing, University of Manchester.
29th April 2004.
Change Log
Author
Andrew Porter
Comments
As released with v.1.1 of the RealityGrid
steering software.
Date
29th April 2004
Acknowledgements
The RealityGrid Steerer is mainly the work of Sue Ramsden, with some further enhancements by
Mark Riding and Andrew Porter. The steerer is built using the RealityGrid Steering API, by
Andrew Porter.
Introduction
The RealityGrid Steerer is a generic user interface for performing computational steering on
(computational) jobs which have been built using the RealityGrid Steering API. This document
aims to give new users an overview of how to use the steerer, and to explain the functionality
which it offers.
1
Starting the Steerer
Environment set-up
The steerer requires that some environment variables be set before it is executed. The main one of
these is REG_STEER_HOME which should contain the path of the directory containing the
steering library (e.g. /home/zzcguap/projects/reg_steer_lib). If the steering library is not available
then any valid path will suffice.
If local (file-based) steering is being used then REG_STEER_DIRECTORY should contain the
path to the directory to use for steering communication. This should match the value of
REG_STEER_DIRECTORY passed to the steered application.
Alternatively, if remote steering (using Grid Services) is to be used then REG_SGS_ADDRESS
should be set to the address of the Steering Grid Service of the steered application. The value
given in this environment variable can be edited from within the steerer (see later) or,
alternatively, specified on the command line.
Launching
Run the steering application by executing the command ‘steerer’ at the command prompt
(assuming that it is in your path). You will be presented with a simple start-up screen:
Steerer startup screen
The Steerer menu
Steerer menu
The Steerer menu has four options:
• Local Attach
attach to a local steerable job, communicated with by means
of a local, shared file system. Shortcut Ctrl+A
• Grid Attach
attach to a steerable job located on ‘any’ machine,
communicated with by means of a Grid-Service interface.
Shortcut Ctrl+G
2
•
Set Polling Interval
•
Quit
Set how often (in seconds) the steerer polls the computational
job. Shortcut Ctrl+P
Quits the application. Shortcut Ctrl+Q
The Polling Interval is an important parameter since it controls how often the steerer checks for
status messages from an attached application. If the steerer fails to “keep up” with the application
then status messages will be lost which may result in strange behaviour. For applications that
generate many status reports per second, the value of the “STEERING INTERVAL” steerable
parameter should be increased in order to reduce the frequency with which the application
generates status reports. (This steerable parameter is automatically generated by the steering
library and is thus available for all applications that use the RealityGrid steering library.)
Attaching to a steerable job
Selecting Local Attach from the Steerer menu will take you straight to the main RealityGrid
Steerer window. Should the steerer fail to find an application to attach to then the Steerer startup
screen will be displayed with a “Failed to attach” message displayed. If this occurs then check
that the REG_STEER_DIRECTORY environment variable in the steerer’s environment matches
that set for the simulation and that the application is actually running.
Selecting Grid Attach will bring up a small dialog box first:
Grid Attach dialog
The dialog lists available RealityGrid applications and their addresses (handles) in a table. Entries
in the Handle column are fully editable. By selecting an entry in the table and clicking on the
Attach button, a Steerer is created for the chosen application. Should the attach fail then check that
the handle you’ve specified is correct and that the application you are attempting to connect to is
up and running.
It is also possible (on Linux systems) to specify the handle to connect to on the command line
when launching the steerer.
3
Using the Steerer
The Main Window
Steerer main window in local-steering mode
The Main Window is split into five conceptual sections:
• Control Buttons
• Monitored Parameters
• Steered Parameters
• Data IO
• CheckPoint Types
4
Control Buttons
The Control Buttons panel manages overall control of the steerable job’s state. Different buttons
will be greyed out and unavailable depending on a job’s state; for instance, jobs that are not
running cannot be stopped.
• Pause button
pauses a running job
• Resume button causes a paused job to resume
• Stop button
ends the job
• Detach button detaches the steerer from the job, leaving the job running
• Close button
closes the main window of the steerer, returning to the startup screen
• Tell All button causes the steerer to pass any user updated parameters to the job, see
Steered Parameters section, below
Monitored Parameters
The Monitored Parameters table lists parameters which are exposed by the steerable job, but are
not themselves directly steerable. An example of a monitored parameter for a simulation job might
be time per simulation step. Such a parameter is changed only by the steered application itself, not
the user.
The Steerer allows graphs to be drawn of monitored parameters. By right clicking on a monitored
parameter, a context menu appears allowing the user to select a ‘Draw History Graph’ option.
Draw History Graph context menu option
5
Parameter History Graphs
Selecting the Draw History Graph option from the context menu causes a new window to appear,
containing a simple 2D line plot of the selected parameter’s history. The graph is constructed
simply by connecting adjacent ordinates with straight lines – no fitting is performed.
Example Parameter History Graph
There are two menu’s available in this window, the File menu, and the Graph menu.
Parameter History Graph: File menu
The File menu has four options:
• Print
requests a print-out of the image portion of the window. Shortcut Ctrl+P
• Save
saves the image portion of the window to disk. Shortcut Ctrl+S
• Save data saves the raw data to file (pops up a file browser). Shortcut Ctrl+t
• Close
closes the window. Shortcut Ctrl+C
6
Parameter History Graph: Graph menu
The Graph menu also has four options:
• Auto Y Axis
allows the application to automatically determine the extents
of the y-axis. This menu item toggles on and off. Shortcut
Ctrl+A
• Define Y upper-bound
if Auto Y axis is not selected, this menu item becomes
available. By selecting it, a dialog appears (see below)
allowing you to enter an upper bound for the Y axis. If Auto
Y Axis is reselected, then this value is ignored. Shortcut
Ctrl+U
• Define Y lower-bound
as ‘Define Y upper-bound’, but for the lower bound. Shortcut
Ctrl+L
• Toggle display of symbols enables/disables the display of symbols at data points.
Shortcut Ctrl-D
Symbols are displayed by default if the graph is of an appropriate scale – if resolution does not
permit then they are automatically hidden.
Y axis upper-bound dialog
Note that the steering client automatically logs the values of all monitored parameters (irrespective
of whether they are being plotted) and therefore if it is connected to a running simulation for an
extended period it may accumulate a considerable amount of data. Displaying a history plot of a
large data set obviously uses some computational resource, particularly if the plot is being updated
frequently. Therefore it is recommended (in order to maximise the responsiveness of the steering
client) that history plots be closed while not in use if the steering client is being used to
continuously monitor long runs.
7
Steered Parameters
The Steered Parameters list box contains a list of all steerable parameters exposed by the current
job. The first column, ‘Name,’ lists the names of each of the parameters, the second, ‘Value,’
shows the current value for each parameter, and the third, ‘New Value,’ allows you to enter new
parameters. Hovering the mouse over an entry in the third column brings up a tool tip showing the
minimum and maximum allowable values for that parameter. If the steerable parameter is a string
then the maximum allowable value gives the maximum length of the string.
New values are only propagated to the running job once the entry has been completed (by pressing
Enter or leaving the cell via the cursor keys) and the ‘Tell’ button is clicked. When this happens
the entries in the ‘Value’ column are updated to reflect the new values, and any entries in the
‘New Value’ column are cleared. This action is also performed if you click on the ‘Tell All’ button
in the Commands button panel. Note that the entries in the ‘Value’ column are only updated upon
confirmation from the application – this thus provides confirmation that it has received the
instruction(s).
Steered Parameters tool tip
8
Data IO
The Data IO table lists all data input and output channels supported by the current job. The
‘Name’ column lists the name of each channel, the ‘Freq’ column lists how often data is written to
or read from the channel (in time steps), the ‘New Freq’ column allows you to specify a new
frequency for each item, and the ‘IO Type’ column indicates whether the channel is for input or
output. Each individual entry is either an input or an output, not both. As with the steered
parameters table, updates made are not propagated to the current job until either the ‘Tell Freq’s’
button or the ‘Tell All’ button in the Commands button panel is clicked.
It is possible to manually request that data be emitted/consumed, in addition to the automatic
events. To do so, select an entry from the table, and click on the ‘Consume’ or ‘Emit’ button at the
right of the table. Only one of the buttons will be available for each entry, depending on whether
the data channel is for input or output.
Main Window Data IO Table selection
9
CheckPoint Types
The CheckPoint Types table lists the types of checkpoint that the running job supports. There can
be many instances (checkpoints) of each checkpoint type, and a job may expose several
checkpoint types which differ in the parameters and data values they record. The majority of jobs
will only need a single checkpoint type.
Main Window CheckPoint Type selection
The ‘Name’ column lists the names of each checkpoint type, the ‘Freq’ column lists the frequency
with which checkpoints are automatically taken (in time steps), and the editable ‘New Freq’
column allows you to enter new values for a checkpoint’s frequency. As with the Steered
Parameter values, new frequency values are only propagated to the running job when either the
‘Tell Freq’s’ button or the ‘Tell All’ button in the Commands button panel is pressed.
There are slight differences in the steerer main window depending on whether local (file-based) or
remote steering (using the grid-service framework) is being performed.
Checkpointing with local steering
Checkpoints (checkpoint type instances) can be created or used to perform a restart by means of
the ‘Create’ and ‘Restart’ buttons to the right of the main checkpoint table. These buttons will be
10
greyed out and unavailable by default, only becoming active if an appropriate checkpoint type has
been selected.
After clicking on the Create button for a valid checkpoint type, the application will be instructed to
create a checkpoint instance of the selected checkpoint type.
After clicking on the Restart button for a valid checkpoint type, a dialog is presented listing all the
checkpoint instances for that type. You can select a checkpoint instance from the list, and instruct
the application to restart from it by clicking on the ‘Restart’ button. Clicking on ‘Cancel’ quits the
dialog without doing anything.
CheckPoint Selector dialog
In order to help differentiate between checkpoint instances, it is possible to inspect the parameters
of each by clicking on the ‘Parameters’ button. This brings up another dialog, which lists the
checkpoint instance’s parameters and their values at the time the checkpoint was taken. It is
possible to have several Checkpoint Parameters Table dialog’s open at the same time, so that
different checkpoint instances can be compared and contrasted.
Again, clicking on the ‘Cancel’ button closes the dialog.
CheckPoint Parameters Table dialog
11
Checkpointing with remote steering
When remote steering is in operation, the main window of the steerer and the way in which a
restart is performed is slightly different.
Steerer main window in remote-steering mode
A checkpoint is still created by selecting the appropriate checkpoint type from the checkpoint table
and clicking the `Create’ button. However, the `Restart’ button is now located in the panel at the
top of the window – this is because it is no longer necessary to select a checkpoint type before
pressing it. Instead, on pressing `Restart,’ the user is prompted to enter the Grid Service Handle of
a suitable checkpoint. How the user obtains this GSH is beyond the scope of this document since
it relies upon the user browsing a checkpoint tree (using either a web interface or some tool such
as the RealityGrid launching wizard).
12
Index
A
Attach · 2
C
CheckPoint Types · 10
Checkpointing with local steering · 10
Checkpointing with remote steering · 12
Control Buttons · 5
D
Data IO · 9
E
Environment set-up · 2
I
Introduction · 1
M
Monitored Parameters · 5
P
Parameter History Graph · 6
Polling Interval · 3
Printing graphs · 6
S
Starting the Steerer · 2
Steered Parameters · 8
13